Drafting instrument



United States Patent 3,181,243 DRAFTING INSTRUMENT Thaddeus T. Zajac, 2704 W. 24th Place; Louis A. Osowski, 2153 W. 18th St; and Joseph Michalowski, 2700 W. 24th Place, all 'of Chicago, Ill.

Filed June 5, 1963, Ser. No. 285,677 12 Claims. (Cl. 33-104) This invention relates to a drafting instrument and more particularly to a drawing tool which is particularly adapted for line drawing though not necessarily restricted thereto.

Drafting instruments in current use generally use translucent or transparent materials such as Lucite or Celluloid and the like to facilitate drafting work.

In drawing particularly, it is necessary to space the scribing edge from the paper to prevent the ink from running along the edge. It is also necessary to illuminate the work area to insure accuracy and facility.

It is a general object of this invention to provide a novel drafting instrument which incorporates a novel spacer which serves as illumination means for directing light to the drawing edge of the instrument.

A further object of the invention is to provide in a drafting instrument made of transparent plastic material a novel spacer in the form of a light-directing prism oriented to illuminate the ruling edge.

Another object of the invention is to provide a novel drafting instrument with a plurality of angularly arranged sections which spreads the seating area of the instrument against the work.

A further object of the invention is to provide a novel drafting instrument which gathers the incident light and directs it to the ruling edge.

Another object of the invention is to provide a drafting instrument such as a triangle or the like in which the prism-like light-diffusing structure also serves to reinforce the flat, generally thin plastic body of the instrument.

A more specific object of the invention is to provide a novel drawing instrument which comprises a thin, flat body providing a ruling edge and which has an embossment on one side which provides a spacer for the edge, said embossment being spaced transversely of the edge to accommddate tilting of the instrument toward and away with respect to the drawing.

A still further object is to provide a drafting instrument comprising a flat body with a prism-like embossment which extends adjacent to the ruling edge of the instrument along the full length thereof and in which different segments of the embossment are of different depth and configurations in order to properly diffuse the light along the ruling edge.

These and other objects and advantages inherent in and encompassed by the invention will become more apparent from the specification and the drawings, wherein:

FIGURE 1 is an obverse side plan view of a drafting instrument incorporating the invention;

FIGURE 2 is an edge view;

FIGURE 3 is a fragmentary edge view illustrating the instrument in use tilted toward the drawing;

FIGURE 4 is an enlarged fragmentary reverse side view illustrating the invention in greater detail; and

FIGURE 5 is an enlarged sectional View taken substantially on line 5--5 of FIGURE 4.

Describing the invention in detail, the drafting instrument 2 comprises a triangle having side ruling edges 3 and 4 and a hypotenusal ruling edge 5. The body portion 6 of the instrument is relatively flat having an obverse face or side 7 and a reverse side 8. The body 6 as well as the entire instrument is formed of transparent plastic material through which light passes into the prism embossments 9, 10 and 11 formed respectively on the legs 3,181,243 Patented May 4, 1965 12, 13 and 14 of the triangle on the reverse side of body 6.

The embossment 9 has a plurality of segments 9, 9' which are interconnected at obtuse angles and the apices of juncture 9a and 9b are alternately directed toward edge 3 and the paralleling inner edge 3' of leg 12.

Similarly the embossment 10 has its segments 10', 10' interconnected at apices 10a, llib which are respectively directed toward the ruling edge 4 and the inner edge 4 of the leg 13.

The embossment 11 along the edge 5 also has a plurality of segments 11', 11 in obtuse arrangement with apices 11a, 1111 which are respectively directed toward edges 5, 5'. The angles between sections 11', 11' are between 145 175 whereas those between sections 9', 9' and 10', 10 are of the order of -14().

There is provided a straight embossment 16 inwardly of the embossment ll. Embossment 16 is located substantially medially between said embossment 11 and the edge 5.

Opposite ends of embossment 16 terminate in cylindrical bosses 17, 18 into which also merge opposite ends of the embossment 11. One end of embossment 9 merges into the boss 17 and one end of embossment 10 merges into the boss 18.

These embossments 17 and 18 are located centrally on the bisectors of the angles 20 and 21 and boss 23 is located on the bisector of the angle 24 and joins the adjacent ends of straight embossments 25 and 26 which respectively parallel edges 3 and 4 and are also respectively formed on legs 12 and 13. Embossment 25 merges into boss 18 and intersects the portions 9', 9' of embossment 9. Embossment 26 intersects portions 10, 10' of embossment 10 and merges into boss 17 It will be realized that each embossment is triangular in cross-section and comprises a vertical light-emitting side or face 30 which faces toward the adjacent ruling edge and a sloping side 31 remote from the adjacent ruling edge.

The light which is transmitted through the obverse or top side 7 is redirected through the prism embossments toward the adjacent ruling edge to illuminate the area.

It will be noted that the bosses 17, 18 and 23 as well as intermediate bosses 33, 34 and 35 formed respectively on legs 12, 13 and 14 are of greater height than the embossments to prevent damage thereto.

The embossments, however, do provide a stiffening ribbing transverse to the plane of the body 6.

The prism embossments 25 and 26 are of lesser depth than that of the segments 9, 10', whereby the portions of these segments behind the embossments 25 and 26 are adapted to direct the light thereunder.

In view of the disposition of embossment 11 ahead of embossment 16 as respects the ruling edge 5, the former is shallower than the latter.

We claim:

1. In a drafting instrument, a light transmitting relatively fiat body having a ruling edge, a light directing prism integral with the body and extending along said ruling edge and having a light-emitting face directed toward the ruling edge and extended below the edge and in close proximity thereto.

2. The invention according to claim 1 and said prism being an embossment on the body and having at least a portion with angularly related interconnected segments disposed transversely to said edge.

3. The invention according to claim 1 and said body having a plurality of bosses thereon of greater depth transversely of the body than the prism for spacing the prism from associated work on which said instrument is used.

4. The invention according to claim 3 and said prism and bosses being embossments on one side of the body and said bosses being of limited dimension and providing fulcrums accommodating canting of the body to bring the ruling edge toward the associated work.

5. In a drafting instrument, a triangular light-transmitting generally fiat body having a pair of side legs and a hypotenusal leg, each leg presenting a ruling edge, a light-directing prism embossment on each leg along said ruling edge for directing light thereto.

6. The invention according to claim 5 and each said embossment comprising a plurality of segments extending transversely of the related ruling edge.

7. The invention according to claim 6 and a further prism embossment on each leg extending generally parallel to the related ruling edge.

8. The invention according to claim 7 and a spacer boss on each corner of the body of greater depth than said prism embossments.

9. In a drafting instrument, a flat, translucent body with a ruling edge and having a length and width, and combination body reinforcing and light-directing means integral with the body and extending below the ruling edge for directing light to said ruling edge and including portions extending lengthwise across the width of the body.

10. The invention according to claim 9 and said means comprising embossments on said body having a plurality of angularly related interconnected segments disposed in intersecting relation to the ruling edge.

11. The invention according to claim 10 and said segments presenting a plurality of apices directed toward said ruling edge.

12. The invention according to claim 11 and said means comprising a plurality of prism embossments on the body of different depth and oriented to direct light toward said ruling edge, said embossments comprising portions extending lengthwise diagonally with respect to the ruling edge.

References Cited by the Examiner UNITED STATES PATENTS 1,800,452 4/31 Karnasch. 2,563,191 8/51 Russ. 2,673,288 3/54 Stevens 240 -1 FOREIGN PATENTS 846,968 8/52 Germany.

ISAAC LISANN, Primary Examiner. 

1. IN A DRAFTING INSTRUMENT, A LIGHT TRANSMITTING RELATIVELY FLAT BODY HAVING A RULING EDGE, A LIGHT DIRECTING PRISM INTEGRAL WITH THE BODY AND EXTENDING ALONG SAID RULING EDGE AND HAVING A LIGHT-EMITTING FACE DIRECTED TOWARD THE RULING EDGE AND EXTENDED BELOW THE EDGE AND IN CLOSE PROXIMITY THERETO. 